FMA Direct
– 15 –
Co-Pilot™ user’s guide
At the field
When using Co-Pilot™, you’ll need to add two routines to your
normal pre-flight checks
at the field
:
Infrared field calibration
— before your first flight of the
day, and any time there is a significant change in the weather.
Co-Pilot pre-flight check
— before each flight, as part of
your regular pre-flight check.
These procedures are described on the following pages.
About the infrared field calibration
The infrared field calibration enables Co-Pilot™ to measure the
environment in which it will be flying. The calibration has two
parts:
1. Co-Pilot™ determines the infrared temperature difference
between sky and ground.
When this step is complete, Co-Pilot™ tells you the infrared
temperature difference by cycling the servos. Co-Pilot™
works well with moderate to high temperature differences, but
is less effective with a very small temperature difference. By
counting the servo cycles, you can decide whether conditions
are favorable for flying with Co-Pilot™.
This step also enables Co-Pilot™ to determine when full pitch
correction is needed. For example, when the aircraft is
heading directly for the ground, Co-Pilot™ will apply
maximum pitch correction.
2. Co-Pilot™ determines how the infrared horizon appears
when the aircraft is level.
This enables it to compensate for
minor Sensor tilt (for example, caused by dihedral when the
Sensor is mounted on a wing). Co-Pilot™ sets its own trims
for level flight.
Co-Pilot’s Sensor sees for many miles in all directions when the
model is airborne. Its field of view will include grass, trees,
buildings, pavement, people, cars, clouds, water and many
other objects with different infrared emissions. The Sensor de-
tects an average infrared temperature sufficient for Co-Pilot™ to
carry out flight stabilization under nearly all conditions.
During calibration, Co-Pilot’s Sensor sees infrared temperatures
in the immediate vicinity of the model. This means that you
should calibrate over an area representative of the general in-
frared environment—such as grass—the Sensor will see when
the model is airborne. Once calibrated, large variations in ter-
rain or weather can affect Co-Pilot’s ability to stabilize the air-
craft. If these occur, you may need to recalibrate.
The calibration procedure recommends that you
not
calibrate,
for example, over asphalt (such as a taxiway, runway or parking
lot). If you were to calibrate over asphalt, the Sensor would de-
tect the infrared generated by the asphalt—not the average for
the larger area in which the model will be flying—resulting in a
falsely high temperature difference.
Co-Pilot™ conveniently tells you about the infrared temperature
difference it measures on a relative scale of one (small differ-
ence) to ten (large difference). In two years of testing Co-
Pilot™, we’ve made some important observations:
Co-Pilot™ rarely measures a difference of 10.
Co-Pilot™ even more rarely measures a difference of 1.
Readings of 1 have only been seen over snow, in fog and
when the cloud cover is below two hundred feet. Not many
people will fly in those conditions.
More about infrared field calibration
CAUTION:
If you are at or near a flying field, observe
frequency control rules and comply with local proce-
dures before turning on your transmitter. When the
transmitter is on—
even for a few seconds
, it is radiat-
ing radio frequencies which may interfere with a radio
system already operating on the same frequency.
CAUTION:
Read safety precautions on page 3 be-
fore flying with Co-Pilot™.
What happens if you use Co-Pilot™ under the worst possible
conditions? When Co-Pilot™ doesn’t see a significant differ-
ence in infrared temperature, it doesn't issue any compensating
signals to the receiver.
If the model is trimmed for stable
flight
, it simply responds to your commands as though Co-
Pilot™ weren’t in the system. We recommend that you deacti-
vate Co-Pilot™ (turn the “Throw” control fully counterclockwise)
if it produces a reading of 1 during calibration. Otherwise, you
may experience unexpected flight excursions.
What happens if you calibrate over land and fly over water? If
you fly near a small lake, the Sensor doesn’t see much of a
change. If you fly over a larger body of water, the Sensor sees
a somewhat lower average infrared temperature compared to
flying over land. All you need to do in this situation is make sure
Co-Pilot™ measures a moderate to high temperature difference
(4 or higher) over land. Co-Pilot™ sees a 1 unit drop for each
6º of lower temperature difference. For example, if the aircraft
is flying over water that is 12º lower than the land where Co-
Pilot™ was calibrated, Co-Pilot™ has 2 units less temperature
difference to work with. If the original calibration number was 5,
then the effective calibration number would be 3 over water.
However, if Co-Pilot sees a 2 over land, it would see 0 over wa-
ter. It is safer to fly over large lakes when the temperature dif-
ference is 4 or higher over land.